Beasts like the original Denon 5000 were great. However, KAL is correct. Missing things like DPL II, 24/96 and much more makes a huge difference. The last of the 5.1's that I'd consider would be an Anthem AVM-2 or perhaps a Sunfire. Who cares if a unit is 7.1, you don't have to use all of the channels.
As a 2 channel rig, an older Denon or B&K can be awesome.
As a 2 channel rig, an older Denon or B&K can be awesome.